A flange connection for connecting metallic pipes is shown in German Patent 410080 wherein the coupling is formed by a recess in the pipe and wherein an inner flange ring is developed in two or more parts. The divided inner flange ring makes it possible to radially push the ring on to the pipe part, which provision is indispensable when using the device with an armature or fitting since, in such situations, the flange ring cannot be inserted over the pipe from the other end. In that apparatus, however, it is a disadvantage that the mounting is very cumbersome since the multiple part inner flange ring must be held in position until an outer flange ring can be pushed over it. When using this apparatus on large dimension flanges, the assembly can hardly be accomplished by one person. Moreover, there is the disadvantage that the individual parts of the inside flange ring can tip during the bracing or connection process in which case they do not fit evenly against the outside flange ring, resulting in uneven clamping forces and the loss of the advantage which would otherwise be provided of cone shaped supporting surfaces which are provided to prevent tipping moments at the location of the joint.
Whenever the coupling members are deformed by bending forces and unilateral introduction of force, then a tight connection of the tubular parts can not be achieved with the flange connection. Particularly when the parts are made from a polymeric or plastic material, such deformations occur easily in prior art flange connections and ruptures of the plastic coupling members or leaky connections occur.